Baby nipple



June 1963 c. H. SCHAAR BABY NIPPLE Filed April 17. 1961 United States Patent 3,092,276 BABY NIPPLE Charles H. Schaar, Chicago, I-lL, assignor to The Kendall Company, Boston, Mass, a corporation of Massachusettts Filed Apr. 17, 1961, Ser. No. 110,290 10 Claims. (Cl. 115-11) This invention relates to baby nipples, more specifically to that class of baby nipples wherein the nipple is provided with a radially projecting base flange. When the nipple is in use, this flange normally is clamped near its circumferential edge to the bottle rim by the overlying radial flange of an annular retaining screw cap which screws to the bottle neck. The teat portion of the nipple projects through the opening in the flange of the retaining cap. In the normal construction when the nipple is attached to the bottle but is not in use, the top of the nipple flange is in contact with the underside of the flange of the retaining cap.

It is desirable with baby nipples to provide some means of relieving the partial vacuum created in the bottle when milk is drawn out of the teat. One Way to do this is to put one vor more small holes through the nipple flange inwardly of the clamped portion. Theoretically this would seem to be self-functioning since the vent hole will seal itself by contact with the retaining cap flange and prevent leakage when the bottle is not being used for feeding. When milk is drawn out of the bottle, however, a partial vacuum is created and the pressure of the outside air causes the nipple to move into the bottle, hinging on its clamed circumferential edge portion. As the nipple moves in, the top of the nipple flange gradually separates from the underside of the retaining cap flange until finally the seal is broken around the vent hole and air rushes in to relieve the partial vacuum. At the pressure builds up in the bottle approaching atmospheric pressure, the nipple moves out and the vent hole seals against the underside of the cap flange once more.

While nipples of the type just described have provided some venting without leakage they have not been entirely satisfactory because considerable vacuum must be created in the bottle before the vent opens. In'practice such nipples, which operate with a diflerential pressure in the bottle averaging about 1.35 inches of mercury less than atmospheric pressure, make it diflicult for very small and weak babies to get enough milk before they become tired or for older babies to get suflicient milk in a reasonable time.

It is one of the objects of this invention to provide baby nipples with improved vent operation so that faster feeding with less eflort may be accomplished.

Other objects and advantages of the invention will be apparent from a study of the specification and drawings.

In the drawings:

FIGURE 1 is a top view of a typical improved nipple of this invention as it appears when attached to the bottle in a normal manner.

FIGURE 2 is an enlarged side view partially in section of a typical improved nipple of this invention, separated from the bottle and retaining cap.

FIGURE 3 is a magnified partial plan view of the nipple flange of the nipple of FIGURE 2 showing the relationship between the vent hole and the loci of certain integral nubs projecting upwardly from the nipple flange surface.

FIGURE 4 is an enlarged partialy view in cross section taken along the line 44 of FIGURE 1 as viewed from the direction of the arrows when the bottle is not being nursed.

FIGURE 5 is an enlarged partial plan view similar to that of FIGURE 3 showing the relationship between nipple flange, vent hole and spaced bubble the vent seal is broken.

FIGURE 6 is the enlarged partial plan view of FIG- URE 5 showing the relationship between nipple flange, vent hole and space bubble after the vent seal is broken.

The objects of this invention may be accomplished by providing a nipple whose flange carries on its upper surface an integral pair of upwardly projecting nubs of such height and location from the vent hole as to cause breaking of the vent seal before the vacuum differential has had time to build to objectionable proportions.

It has been discovered that a very critical relationship exists for optimum performance between the height of the nubs and their distance and location from the vent hole edge. If the nubs are too high or are improperly placed too close to the vent hole edge, the latter does not properly seal or is too easily unsealed and leakage occurs whereas if the nubs are too low or are placed improperly too far from the vent hole edge, they are ineffective to achieve the objects of the invention.

Referring once more to the drawings: The teat 11 of the nipple 10 in FIGURES 1, 2 and 4 projects through the opening in the flange 12 of the retaining cap 13. The nipple 10, FIGURES 2, 4, 5 and 6, has a base flange 14 having a vent hole 15 and two upwardly projecting integral nubs 16 and 16a. The retaining cap, FIGURES 1 and 4, has intemal screw threads 18 which screw onto the external threads 19 of the bottle 17 and clamp the nipple flange 14 between the underside 20 of the flange 12 of the retaining cap and the rim 21 of the bottle. The ring stop 24 on the bottle does not contact the cap 13 when the nipple is clamped in place.

In FIGURE 3 the loci of points in each of which a nub should be located to achieve optimum results are indicated by shaded areas a and c. These areas and the area b between them are roughly wedge-shaped like three ieces of pie, each being a 30 wedge with its tip truncated short of its apex along the circumferential line through the vent hole center. Apexes of these wedges fali about A; inch outwardly of the vent hole and on the radial line through the center of the vent hole. The larger arcs of the areas, a, b and 0 lie about /is inch from the center of the vent hole. Nipples with nubs in the area b closer than .1 inch to the vent hole edge have a tendency to leak. Outside the areas of nub placement which produce optimum results, however, there exists a less satisfactory nub location zone d which is shown stippled to indicate its location. Nipples with nubs in this area operate with some reduction of vacuum necessary for vent operation short of optimum but still of value. Nipples with nubs at a greater distance from the vent hole edge than the distance between the vent hole edge and the teat reduce the vacuum necessary for vent operation insignificantly and hence are of no value in achieving the objects of this invention.

A particular nub may have a few or a great many points which contact the underside of the screw cap flange and create a space bubble around it. If the nub is in an effective zone and is of proper height it creates the proper size space bubble and is effective. But if the nub has no point as high as the proper height it creates a space bubble which is too small and hence lt is ineflective. On the other hand if a nub has points in the effective zone which are improperly high the space bubble is so large as to include the vent edge and hence leaking occurs.

A point on a nub to be effective must not only be in an elfective area but it must have a fairly critical height. Variation from this critical height by more than 20% causes either leakage or ineffectiveness.

The effective height of a point on a nub varies in accordance with its shortest distance from the vent edge, being about .007 inch 120% when it is in an optimum area closest to the vent edge at about .006 inch from said edge and increasing in accordance with the following formula:

where h is the height in inches of the point and d is the shortest distance from the point to the vent edge. It is obvious from the previous discussion that a nub in an effective area can have few or many points which conform to the above formula but it must not have any point of greater height than is indicated by the formula considering its shortest distance to the vent edge.

In applying the above formula at nub distances greater than .006 inch, it is preferable to convert the distances to decimals. For instance, if the shortest distance to the vent edge is .0375 inch from a given point on a nub in an effective area the effective height is which equals .014 inch i20%. At inch from a given point to the closest vent edge the proper height would be which would be .0187i20%. At the maximum effective distance of about .132 inch from the vent edge at the closest distance an effective nub height would be .0317-' :20%.

In general, then, it is desirable to provide two nubs, one in each optimum zone and preferably symmetrically placed about the radial line through the vent hole center. The best results are obtained when effective portions of the nubs closest together are about A; inch apart.

The theory of operation which is believed to apply with respect to venting is illustrated in FIGURES and 6. It is believed that when the nipple is in place with the retaining cap locking it to the top of the bottle, that a space bubble exists surrounding the two nubs. When the nubs are within the optimum zone, the space bubble created extends from the nipple teat to just short of the vent hole edge. The vent is surrounded by nipple flange portions which contact and seal against the underside of the retaining flange and thus leakage is prevented. When the nipple moves into the bottle only slightly due to slightly reduced pressure therein, however, the space bubble thickens and is increased in size to include the vent hole. Venting occurs and the nipple again moves out to seal the vent. In the area d the location of nubs is such that the nipple must move further into the bottle than it does when the nubs are in the areas a and c and hence a higher partial vacuum is built up before the venting occurs.

It is to be understood that the above theory is offered only as a possible explanation of the method of functioning of the nipples of this invention. Whether the theory is the true explanation of what happens is not known but this invention does provide a nipple which increases the rate of feeding and reduces the effort necessary to draw milk from the bottle. The validity of the claims of this invention, therefore, does not depend upon the correctness of any theory of operation.

Nipples of this invention are capable of reducing the partial vacuum for vent operation to the point where only .7 to .6 inch of mercury reduction of pressure from the atmosphere will cause venting. This is sufficiently low that even the weakest normal baby will have no difficulty in drawing milk from the bottle but at the same time the flow is controlled as is not the case when the teat milk hole is increased in size.

Example 1 A nipple without the nubs of the nipples of this invention but otherwise identical to the nipples used in the other examples was used as a control. This nipple had a flange .283 inch in width and a vent hole .012 inch in diameter located .129 inch from the flange rim. The vent hole top edge was a circle of about .05 inch diameter. This nipple was placed on a bottle apparatus consisting of a normal bottle with its bottom modified to permit measurement of pressure reduction from atmospheric pressure in inches of mercury. The nipple was clamped to the rim of the modified bottle with a normal retaining cap with its vent hole about inch from the bottle rim and with the teat projecting through the radial flange of the retaining cap. The retaining cap was tightened to three degrees: loose, normal and tight using a torque wrench. The torque wrench was adjusted to produce the normal tightness usually applied by hand and the cap was given a /4 inch further turn around its circumference to obtain the tight position and a /4 inch turn from the normal position in the opposite direction to obtain the loose position. Means were applied to the nipple for obtaining positive suction and the milk in milliliters obtained by a continuous suction of 2 inches of vacuum for five minutes was measured. The reduction of pressure in the bottle averaged 1.33 inches of mercury before the vent opened. There was no leakage. In five minutes the milk obtained average 40 milliliters.

Example 2 A nipple of the invention having two nubs each of about .004 square inch area symmetrically placed about the radial line through the vent hole and having their closest edges about inch apart and having their closest points at about inch from the vent hole center or about .0375 inch from the vent edge in the areas a and c was tested on the identical apparatus used in Example 1 in the same way using the identical suction. The reduction in pressure before the vent opened with the nubs having a height of .007 inch averaged 1.33 inches of mercury. In five minutes an average of 40 milliliters of milk was obtained. This is not, of course, any significant improvement. By increasing the nub height to .014 inch, however, other conditions remaining the same, the reduction in pressure before the vent opened averaged .7 inch of mercury. In five minutes an average of 57 milliliters of milk was obtained. Increasing the nub height to .021 inch caused the vent to leak without appreciable reduction in pressure or increase in volume of milk obtained.

Example 3 A nipple of the invention having two nubs each of about .004 square inch area symmetrically placed about the radial line through the vent hole and having their closest edges about A inch apart and having their closest points slightly over inch from the vent hole center and about .11 inch from the vent edge in the area d of FIG- URE 3 was tested on the identical apparatus in the same way using the identical suction. The reduction in pressure before the vent opened with the nubs having a height of .007 inch was not significant over the nipple of Example 1. When the nub height was increased to .014 inch there was reduction in pressure before the vent opened averaging .96 inch. In five minutes an average of 42.5 milliliters of milk was obtained. An increase in nub height to .028 inch did not show an appreciable improvement over the nipple with .014 inch high nubs but did not cause the nipple to leak.

Example 4 A nipple of the invention having two nubs each of about .004 square inch area symmetrically placed in the areas a and c of FIGURE 3 with their closest edges about 5 inch apart and about & inch from the vent hole center and about .006 inch from the vent edge and on the circumferential line through the vent hole center was tested on the identical apparatus of Example 1 in the same way using identical suction. The reduction in pressure before the vent opened with the nubs having a height of .007 inch averaged .66 inch of mercury. In live minutes an average of 50.6 milliliters of milk was obtained. When the height of the nubs was increased to .014 inch the vent hole leaked.

Example 5 A nipple of the invention having two bar-shaped nubs each about A inch wide and about inch long and .007 inch high placed symmetrically on either side of and parallel to the radial line through the vent hole and having their closest edges about & inch apart and being about 4 inch from the vent hole and .006 inch from the vent edge was tested on the identical apparatus used in Example 1 in the same way using the identical suction. The reduction in pressure in the bottle before the vent opened averaged .7 inch of mercury. In five minutes an average of 57 milliliters of milk was obtained. When the height of the nubs was increased to .014 inch, the vent hole leaked.

Example 6 A nipple of the invention having two bar-shaped nubs each about inch wide and about inch long and .014 inch high placed symmetrically on either side of and parallel to the radial line through the vent hole and having their closest edges about V inch apart and being about hi inch from the vent hole and about .0375 inch from the vent edge was tested on the identical apparatus used in Example 1 in the same way using the identical suction. The reduction in pressure in the bottle before the vent opened averaged .6 inch of mercury. In five minutes an average of 55.3 milliliters of milk was obtained. When the height of the nubs was increased to .021 inch the vent hole leaked.

With regard to vent holes, it is almost impossible to punch small holes through soft rubber of the type usually employed in nipple manufacture and obtain cylindrical edges. As a consequence of the yielding nature of the rubber, the holes normally have enlarged diameters at the flange surfaces and taper off to the effective diameter somewhere in between. The preferred nipples of this invention have their smallest or effective vent diameters in the range of about .008 to .02 inch. Vent holes with effective diameters smaller than .008 are difficult to make and certainly offer no advantages. If made too small, of course, they cause slow venting. Likewise, vent holes with their effective diameters larger than .02 inch have no advantages and have a somewhat greater tendency to leak.

In order to function properly, the vent hole obviously should not be entirely clamped between the bottle rim and retaining cap flange. At least a portion of the hole must project into the bottle so that air can pass into the bottle when the nipple is pushed in. It is preferred that the entire vent hole he inwardly of the inner edge of the bottle rim and that at least the upper vent edge be adjacent the bottle rim. This position is atained using bottles of normal thickness by providing the effective vent hole location in the range of .12 to .135 inch measured from the nipple flange edge.

While normally the top edge of the vent hole is created in punching the vent and hence is somewhat larger in diameter than the effective vent hole, the nipple may have a Well or depression in the top so that the vent has its effective diameter in a thinned portion of the nipple flange. For purposes of this invention, the edges of such a well or depression are considered the vent edges. There are, of course, limitations as to how far toward the teat such a well may extend without causing leakage. In general, I have found that when the vent edge projects toward the teat more than .160 inch from the flange edge leakage may occur. Normally, as the vent edges are separated in the circumferential direction of the flange greater than .05 inch, the areas a and c are reduced and the area b increased. But there is no advantage in increasing the edge perimeter of the vent beyond the circumference of a .05 inch diameter circle.

In general, it is preferred that the nipples of this invention be molded of soft rubber but the invention obviously is not dependent upon that specific material and any plastic or rubberlike material suitable for ordinary baby nipples may be used. Specifically and without limitation of this invention thereto, such materials as rubbery vinyl polymers and copolymers, polyurethene rubbers, halogenated polyethylene rubbers, silicone rubbers and rubbery polyamides may be used in addition to all of the usual synthetic rubbers.

With regard to milk outlets, the preferred outlet is a punched hole such as 22 in FIGURE 2 in the range of .008 to .017 inch effective diameter but the outlet may be one or more slits such as 23 in FIGURE 1 or a combination of a hole with one or more slits.

I claim:

1. An integral baby nipple comprising a radially extending base flange, an outer clamping rim portion of said flange for clamping said nipple to a bottle, an upper vent edge surrounding a vent hole extending through the thickness of said flange situated adjacent to but inwardly of said clamping rim portion, and centrally located on said flange and covering an opening therein, an upstanding hollow teat having a milk outlet in the tip thereof, said nipple being characterized in that from the upper surface of said flange at least two separated nub portions project upwardly, no part of any said nub portion in certain effective areas being higher and at least part of each of said two nub portions being of the height of the formula:

where h is the height in inches of the nub in the efiective area and d is the shortest distance in inches from any point having the given height in the effective areas to the upper vent edge, said effective areas including three areas bordering a fourth and ineffective area, two of said areas having as side boundaries with said ineffective area, lines inclined toward said upper vent edges at an angle of 15 to and on each side of the line from the center of the nipple to the center of the vent edge and passing at the closest point to said vent edge at .006 inch outwardly thereof, other perimeter portions of said two areas being arcs of a circle through the center of said vent edge and concentric with said nipple flange edge and a line being the locus of points having the same distance from the vent edge as does the closest point of said teat and join- 7 ing said respective arcs and said inclined lines, the third said effective area being a ribbonlike band one of whose side edges forms a common border with said fourth and ineffective area, being the locus of points about .1 inch from said vent edge, the other of whose side edges being a continuation of the border of said two efleotive areas the locus of points having the same distance from the vent edge as does the closest point of said teat, the end edges of said band being the inclined lines.

2. The nipple of claim 1 wherein the nub portions are separate, each being of an area not greater than .004 square inch.

3. A nipple of claim 1 wherein the milk outlet has an opening in the range of .008 to .017 inch diameter and the vent hole has an opening in the range of .008 to .02 inch diameter.

4. A nipple of claim 1 wherein the nub portions are separated on one end and connected on the other.

5. A nipple of claim 1 wherein the vent hole is situated in the range of from .12 to .135 inch from the flange edge.

6. A nipple of claim 1 wherein the milk outlet is formed by at least one slit.

7. An integral baby nipple comprising a radially extending base flange, an outer clamping rim portion of said flange for clamping said nipple to a bottle, an upper vent 7 edge surrounding a vent hole extending through the thickness of said flange situated adjacent to but inwardly of said clamping rim portion, and centrally located on said flange and covering an opening therein, an upstanding hollow teat having a milk outlet in the tip thereof, said nipple being characterized in that from the upper surface of said flange at least two separated nub portions project upwardly, no part of any said nub portion being higher and at least part of each of said two nub portions being of the height of the formula:

where h is the height in inches of the nub in the effective area and d is the shortest distance in inches from any point having the given height to the upper vent edge, said parts of said two nubs having the formula height being located in an area no farther from said teat than is the center of said vent edge and no farther from said edge than is the closest point of said teat from said vent edge but outside a wedge-shaped area within .1 inch of the vent edge and symmetrically extending 15 degrees on each side of the radial line from said teat to the center of said vent edge, said wedge-shaped area having an apex on said radial line about Ms inch outwardly of said vent hole center.

8. An integral baby nipple comprising a radially extending base flange, an outer clamping rim portion of said flange for clamping said nipple to a bottle, an upper vent edge surrounding a vent hole extending through the thickness of said flange situated adjacent to but inwardly of said clamping rim portion, and centrally located on said flange and covering an opening therein, an upstanding hollow teat having a milk outlet in the tip thereof, said nipple being characterized in that two nubs project upwardly from the upper surface of said flange, the highest point on each of said nubs being .014 inch:20%, said nubs being symmetrically disposed about the radial line from said nipple center to the center of said upper vent edge with their respective highest points being in the range of .06 to .2 inch apart, said upper vent edge measuring in the range of .01 to .05 inch in diameter, the highest points of each of said nubs measuring about .04 inch from said upper vent edge at their closest distances.

9. A baby nursing assembly comprising a bottle having an externally threaded open end, a retaining screw cap having an internally threaded portion fitting and engaging the externally threaded end of said bottle, said screw cap having a radially extending top flange with a central opening therein, an integral baby nursing comprising a radially extending base flange, smaller in diameter than the threaded portion of said screw cap, the outer rim portion of said base flange being clamped between the top flange of said screw cap and said open end of said bottle, an upper vent edge surrounding a vent hole extending through the thickness of said base flange of said nipple situated adjacent to but inwardly of the clamped area of said outer rim portion, and centrally located on said base flange and covering an opening therein, an integral upstanding hollow teat having a milk outlet in the tip thereof, said teat projecting through the opening in said screw cap flange, said nipple being characterized in that from the upper surface of said base flange at least two separated nub portions project upwardly, no part of any said nub portions in certain effective areas being higher and at least part of each of said two nub portions being of the height of the formula:

where h is the height in inches of the nub in the efiective area and d is the shortest distance in inches from any point having the given height in the effective areas to the upper vent edge, said effective areas including three areas bordering a fourth and inetfcctive area, two of said areas having as side boundaries with said ineffective area, lines inclined toward said upper vent edges at an angle of 15 to and on each side of the line from the center of the nipple to the center of the vent edge and passing at the closest point to said vent edge at .006 inch outwardly thereof, other perimeter portions of said two areas being arcs of a circle through the center of said vent edge and concentric with said nipple flange edge and a line being the locus of points having the same distance from the vent edge as does the closest point of said teat and joining said respective arcs and said inclined lines, the third said effective area being a ribbonlike band one of whose side edges forms a common border with said fourth and ineffective area, being the locus of points about .1 inch from said vent edge, the other of whose side edges being a continuation of the border of said two effective areas, the locus of points having the same distance from the vent edge as does the closest point of said teat, the end edges of said band being the inclined lines, said nub portions projecting upwardly from said base flange creating between said base flange and the top flange of said screw cap a space bubble extending from the opening in said top flange adjacent to but short of said upper vent edge.

10. A baby nursing assembly comprising a bottle having an externally threaded open end, a retaining screw cap having an internally threaded portion fitting and engaging the externally threaded end of said bottle, said screw cap having a radially extending top flange with a central opening therein, an integral baby nursing nipple comprising a radially extending base flange, smaller in diameter than the threaded portion of said screw cap, the outer rim portion of said base flange being clamped between the top flange of said screw cap and said open end of said bottle, an upper vent edge surrounding a vent hole extending through the thickness of said base flange of said nipple situated adjacent to but inwardly of the clamped area of said outer rim portion, and centrally located on said base flange and covering an opening therein, an integral upstanding hollow teat having a milk outlet in the tip thereof, said teat projecting through the opening in said screw cap flange, said nipple being characterized in that from upper surface of said base flange two nubs project upwardly, the highest point on each of said nubs being .014 inchi-20%, said nubs being symmetrically disposed about the radial line from said nipple center to the center of said upper vent edge with their respective highest points being in the range of .06 to .2 inch apart, said upper vent edge measuring in the range of .01 to .05 inch in diameter, the highest points of each of said nubs measuring about .04 inch from said upper vent edge at their closest distances, said nubs creating between said base flange and the top flange of said screw cap a space bubble extending from the opening in said top flange adjacent to but short of said upper vent edge.

References Cited in the file of this patent UNITED STATES PATENTS 

9. A BABY NURSING ASSEMBLY COMPRISING A BOTTLE HAVING AN EXTERNALLY THREADED OPEN END, A RETAINING SCREW CAP HAVING AN INTERNALLY THREADED PORTION FITTING AND ENGAGING THE EXTERNALLY THREADED END OF SAID BOTTLE, SAID SCREW CAP HAVING A RADIALLY EXTENDING TOP FLANGE WITH A CENTRAL OPENING THEREIN, AN INTEGRAL BABY NURSING COMPRISING A RADIALLY EXTENDING BASE FLANGE, SMALLER IN DIAMETER THAN THE THREADED PORTION OF SAID SCREW CAP, THE OUTER RIM PORTION OF SAID BASE FLANGE BEING CLAMPED BETWEEN THE TOP FLANGE OF SAID SCREW CAP AND SAID OPEN END OF SAID BOTTLE, AN UPPER VENT EDGE SURROUNDING A VENT HOLE EXTENDING THROUGH THE THICKNESS OF SAID BASE FLANGE OF SAID NIPPLE SITUATED ADJACENT TO BUT INWARDLY OF THE CLAMPED AREA OF SAID OUTER RIM PORTION, AND CENTRALLY LOCATED ON SAID BASE FLANGE AND COVERING AN OPENING THEREIN, AN INTEGRAL UPSTANDING HOLLOW TEAT HAVING A MILK OUTLET IN THE TIP THEREOF, SAID TEAT PROJECTING THROUGH THE OPENING IN SAID SCREW CAP FLANGE, SAID NIPPLE BEING CHARACTERIZED IN THAT FROM THE UPPER SURFACE OF SAID BASE FLANGE AT LEAST TWO SEPARATED NUB PORTIONS PROJECT UPWARDLY, NO PART OF ANY SAID NUB PORTIONS IN CERTAIN EFFECTIVE AREAS BEING HIGHER AND AT LEAST PART OF EACH OF SAID TWO NUB PORTIONS BEING OF THE HEIGHT OF THE FORMULA: 